A common failure mode in construction is a failure to form a durable weatherproof assembly at features such as doors and windows installed within openings of exterior surfaces. Various types of flashing products have been developed, some of which use field-applied strips of adhesive backed sheet products. Other products are field-assembled to flash a portion of an opening, typically the sill or bottom of an opening. These other products help to prevent moisture ingress around such features, but are inherently susceptible to failure, or can become susceptible to failure through improper installation.